Noise testing of gear sets of gears by driving the gears and sensing the resulting vibrations that occur with an accelerometer is a known testing technique. However, during such testing for vibrations it is commonly found that the signal-to-noise ratio of the signal that is sensed by the accelerometer is too low to produce adequate output signals. The present invention substantially improves the signal-to-noise ratio of the output signal by mounting the spindle housing for one of the spindles and resiliently mounting the other spindle housing on a resilient spring system, which is preferably formed by a pair of rectangular-shaped leaf springs. The gears are driven so that the tooth-to-tooth freguency is substantially equal to the resonant frequency of the resiliently mounted spindle housing which achieves a substantial increase in the signal-to-noise ratio of the output signal from the accelerometer.